UCLA Engineers develop smartphone LCDs that harvest light for power

Tired of your smartphone or laptop dying on you? UCLA engineers have figured out a way to use LCD screens to power electronic devices by harvesting energy from surrounding light sources.

Liquid crystal displays, or LCDs, can be found in much of today’s electronics such as TVs, smartphones, computers and more. These displays work using two polarized sheets sandwiching crystal molecules between them which act act as light valves. The combination allows a certain amount of the backlight to escape which creates images on the screen. The problem is that LCDs can suck a lot of power from devices.

Through a research gift to UCLA from Intel and the Office of Naval Research, engineers at the UCLA Henry Samueli School of Engineering and Applied Science found they could increase energy efficiency by equipping devices’ LCD screens with photovoltaic polarizers that converted electricity from ambient light, sunlight and even the LCD’s own backlight. The engineering team calls it a polarizing organic photovoltaic.

“I believe this is a game-changer invention to improve the efficiency of LCD displays,” said Yang Yang, professor of materials science at UCLA and principal investigator behind the research. “These polarizers can also be used to harvest indoor or outdoor light. So next time you are on the beach, you could charge your iPhone via sunlight.”

According to the researchers the current polarized sheets used in LCDs are not efficient enough. Backlights can consume huge portions of a devices power, something like 80 to 90 percent, and as much as 75 percent of that light expelled energy is lost due to the polarizers. The polarizing organic photovaltaic cell aims to catch that energy and turn it back into electricity, though the conversion efficiency of the new polarizers wasn’t stated.